Geared cam expandable interbody implant and method of implanting same

Abstract

A geared cam expandable spinal implant. Rotational motion of a rotating portion is translated into linear motion of a yoke, which moves geared cams at the distal end of the implant to mate with, and walk along, teeth of corresponding racks. The walking of the gear cam teeth along the rack teeth creates a regular rate of implant expansion, reduces initial excessive expansion force applied to the implant, and provides fine adjustment of the expansion rate and force.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a spinal implant, and a method for implanting the implant in a patient's disc space between two adjacent vertebral bodies. More particularly, the present invention relates to an expandable spinal implant including geared cams, configured to expand within the patient's disc space, from a collapsed position to an expanded position.DESCRIPTION OF THE RELATED ART[0002]Expandable spinal implants are known. Existing expandable spinal implants use conventional “4-bar” and “crank slider” expansion mechanisms. Following insertion, while in the collapsed position, into a surgically-enhanced disc space, the existing expandable spinal implants are expanded. The existing expandable implants have been known at least to (1) apply an undesireable excessive initial expansion force to the disc space, (2) apply an irregular expansion force to the disc space, and (3) lack a reliable capability for fine adjustment. Existing expandable implants...

AI Technical Summary

Benefits of technology

This present invention provides an expandable spinal implant that can be inserted into a patient's disc space between two vertebral bodies. The implant can be expanded from a collapsed position to a partially-expanded position and then fully-expanded position to create space between the vertebral bodies. The method of insertion involves using an implant insertion tool that applies a rotational motion to the implant, allowing it to expand and conform to the surrounding anatomy. The tool includes an outer hollow shaft, an inner hollow shaft, and an elongated driver. The elongated driver has a blunt distal end that pushes the implant into the disc space. The invention aims to improve the expandability and conformity of spinal implants in the art.

Problems solved by technology

The existing expandable implants have been known at least to (1) apply an undesireable excessive initial expansion force to the disc space, (2) apply an irregular expansion force to the disc space, and (3) lack a reliable capability for fine adjustment.

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